The Keto Diet for Women
You may have heard that the ketogenic diet is not good for women or perhaps you tried it and noticed changes to your hormones. What time of the month did you start? Did you have more energy or less energy? All of this comes into context when we look at female ketosis.
It may not come as a surprise, but women are biologically different from men. Medical research is still catching up to this “wild phenomenon”. It’s only since 1993 that the National Institute of Health mandated women and people of colour be included in government-funded health research. Whilst progress has been made, the research still has a long way to go, particularly for ketosis states such as time-restricted eating, fasting and the ketogenic diet in female forms. A lot of the information is based on men. Therefore, we must look to the biochemistry of the body and what is happening at a cellular level to assess its effects on women.
What is ketosis?
Ketosis is a metabolic state in which the body burns fat instead of carbohydrates for energy production. A reduction in carbohydrate foods puts your body into a ketogenic metabolic state. During ketosis, the liver produces chemicals called ketones which your cells use for fuel instead of glucose. The ketogenic diet moves your body into ketosis by focussing on restricting carbohydrates and boosting fat sources.
How does ketosis affect women differently?
Ketosis is a fasting state in the body and when you are fasting, the body starts to shut down “non-essential” jobs as it goes into survival mode. This is great if your cells are producing growth activity, such as fat storage, atherosclerotic plaques and cancer cells, as the body sees that as non-essential and shuts it down. However, also included in “non-essential activity” is reproduction. The body doesn’t have time to make a baby when you are in a fasted state as it’s a signal to the body that you are in starvation. This is why one of the biggest symptoms of a long-term keto diet in females is a missing period or hypothalamic amenorrhoea. The body stops ovulating to conserve energy, yet women need ovulation for optimal health. This doesn’t happen to men as the brain doesn’t need to worry about access to additional calories required to grow a baby. There is also evidence to suggest that women fast more efficiently than men (1) meaning women are not required to have long periods of fasting to see benefits. Women burn fat at a quicker rate and ketosis has less impact on the liver compared with men (2). Women also have different cortisol levels across the month which can put a strain on you when fasting. It’s all about doing it at the right time, to support your health.
Carbohydrates and Ovulation
Women need carbohydrates to make the hormones required for ovulation. Ovulation is KEY for female health. Why? Reproductive hormones. Women need both progesterone and estrogens to support the brain, bones, muscles and cardiovascular system.
Not only do progesterone and estrogens support ovulation, but they also take care of a whole host of other biological functions. Let’s look at these powerhouse hormones in more detail:
Progesterone – regulates immune function, supports breast tissue, supports thyroid health, reduces inflammation, is a neuroprotective and regulates nerve cells in the brain. It also supports bone health which is extremely important for premenopausal women as after menopause your bones are more at risk from osteoporosis due to the decline in both oestrogen and progesterone (3).
Oestrogens – there are three major oestrogens - oestrone, oestradiol and oestriol. Together they maintain healthy reproductive structures in the ovaries and womb, build strong healthy bones, keep blood cholesterol low, supports breast tissue, maintain ovulation, protect against cardiovascular disease, supports digestive and gallbladder health (4).
You can see female hormones are not just for reproduction. With healthy ovulation each month, you will ensure long term health for your bones, thyroid, heart, the brain as well as digestion and fertility. As women, we need to be smarter when using a ketogenic diet to get the most out of it, whilst still preserving fertility, because a fertile woman is a healthy woman.
Option 1 - Cyclical Keto
The cyclical keto diet involves adhering to the standard keto diet 5-6 days per week, with 1-2 days of carb consumption. These “re-feeding” days replenish your body’s depleted glucose reserves. You will switch out of ketosis during these days to see the benefits of carbohydrate consumption including boosting muscle growth and improved exercise performance.
This is a great option if you prefer to follow a set schedule during the work week and like to relax your eating regime at the weekends. It can also be a great option post-menopause. Moving into ketosis can take some people 4-5 days, and if that is the case for you this may not be the right option for you.
Option 2 - Cycle Sync Keto
Eating a ketogenic diet in conjunction with your infradian rhythm or menstrual cycle is one of the best ways to preserve reproductive and hormonal health. The cycle sync ketogenic diet involves a standard keto diet from the last day of your menses (bleed) until the day of your ovulation. The day of ovulation differs from woman to woman, but you can be sure of this by temperature, mucus, counting days combined with your energy levels. This method allows for a short period of autophagy and ketone production, while in a metabolically active time in your menstrual cycle. It also supports reproductive health in the luteal phase by ensuring enough carbohydrates to produce progesterone and support oncoming menses, which naturally requires a higher energy intake as you lose cells, tissue and blood.
This option works best for women looking to lose weight or include autophagy, whilst still preserving reproductive health. Ovulation is one of the most energetic times for women as progesterone comes in and levels of oestrogen are tapering so you get the benefits of both hormones. Incorporating higher levels of carbohydrates at this time can help to support your mood, energy and incoming progesterone requirements.
Syncing the ketogenic diet to your Infradian Rhythm gets maximum benefit without compromising your fertility.
A ketogenic diet is a great tool for women to reap the rewards of autophagy and ketone production without fasting. It is especially indicated for conditions such as fatigue, obesity, PCOS and epilepsy. It is best avoided if you have hormonal imbalances such as adrenal or thyroid issues. Please consult a medical practitioner before making any significant changes to your eating regime.
References:
Klempel, M. C., Kroeger, C. M., Bhutani, S., Trepanowski, J. F., & Varady, K. A. (2012). Intermittent fasting combined with calorie restriction is effective for weight loss and cardio-protection in obese women. Nutrition journal, 11, 98. https://doi.org/10.1186/1475-2891-11-98
Browning, J. D., Baxter, J., Satapati, S., & Burgess, S. C. (2012). The effect of short-term fasting on liver and skeletal muscle lipid, glucose, and energy metabolism in healthy women and men. Journal of lipid research, 53(3), 577–586. https://doi.org/10.1194/jlr.P020867
Brinton, R. D., Thompson, R. F., Foy, M. R., Baudry, M., Wang, J., Finch, C. E., Morgan, T. E., Pike, C. J., Mack, W. J., Stanczyk, F. Z., & Nilsen, J. (2008). Progesterone receptors: form and function in brain. Frontiers in neuroendocrinology, 29(2), 313–339. https://doi.org/10.1016/j.yfrne.2008.02.001
Tortora, G. and Derrickson, B., 2014. Principles of anatomy & physiology. 14th ed. Hoboken (Nueva Jersey): Wiley
Paludo, A. C., Cook, C. J., Owen, J. A., Woodman, T., Irwin, J., & Crewther, B. T. (2020). The impact of menstrual-cycle phase on basal and exercise-induced hormones, mood, anxiety and exercise performance in physically-active women. The Journal of sports medicine and physical fitness, 10.23736/S0022-4707.20.10844